WO2007083508A1

WO2007083508A1 - Belt type thickening machine

Info

Publication number: WO2007083508A1
Application number: PCT/JP2006/326199
Authority: WO
Inventors: Tatsuo Hiramatsu; Takao Yoshida
Original assignee: Tomoe Engineering Co., Ltd.; Ashbrook Simon-Hartley Ltd.
Priority date: 2006-01-20
Filing date: 2006-12-28
Publication date: 2007-07-26
Also published as: JP2009101355A; JP4267676B2; JPWO2007083508A1; JP4885244B2

Abstract

[PROBLEMS] The operation of belt type thickening machine is regulated by changing to the flocculation unit, belt running speed and lamp (tilted plate) angle. However, as these are manually operated by operating staff watching the operation condition of thickened sludge, filtrate, etc. discharged from the belt type thickening machine, controlling thereof is difficult. [MEANS FOR SOLVING PROBLEMS] There is provided a belt type thickening machine structured so as to carry out continuous measurement by means of one or two or more of measuring instruments for fed sludge density, thickened sludge density, filtrate density and sludge level on belt and, in accordance with any change of such measurement values, automatically change a flocculation unit aperture or one or two or more of mixer rotation frequency, belt running speed and lamp angle, thereby controlling the density of thickened sludge within a given range.

Description

Specification

Belt type concentrator

Technical field

[0001] The present invention relates to a belt type concentrator used for concentrating surplus sludge, mixed raw sludge, digested sludge, oxidation ditch surplus sludge, factory wastewater sludge and the like generated in a sewage treatment plant.

Background art

Conventionally, the operation adjustment of a belt type concentrator has been performed by changing the aggregating device, the belt traveling speed, and the ramp (inclined plate) angle. These operations are performed manually while observing the operating conditions of the concentrated sludge, filtrate, etc. that the operator discharges from the belt type concentrator.

Disclosure of the invention

Problems to be solved by the invention

[0003] This has the following drawbacks. Operation status confirmation by visual observation of concentrated sludge and filtrate requires the skill level of the operator who has many parts based on the experience of the operator. Since it is not a constant monitoring, the response to changes in operating conditions is delayed. In addition, manual operation adjustment often requires operators to go around the belt-type concentrator, resulting in increased operating costs and a worse working environment. There are also problems such as an increase in the amount of chemicals injected due to a setting value failure of the aggregator and a reduction in belt life due to the belt speed being too high. The present invention has been made to eliminate the above drawbacks.

Means for solving the problem

[0004] The first of the present invention is to constantly measure the supplied sludge concentration with a thermometer and automatically adjust the opening of the aggregating device (mixing valve) according to the change in the supplied sludge concentration. Specifically, when the sludge concentration becomes high, the opening is reduced and the stirring force is increased. Conversely, increase the opening when the sludge concentration is low.

[0005] The agglomeration device (mixing valve) uses a motor-driven valve to adjust the opening degree electrically.

[0006] There is also a method in which a line mixer is used instead of the mixing valve, and the stirring force is adjusted by the number of rotations of the line mixer. Supply sludge concentration is measured by laser beam, microwave, Use a scattered light type densitometer.

[0007] In the second aspect of the present invention, the supplied sludge concentration is constantly measured with a densitometer, and the belt running speed is automatically adjusted according to the change in the supplied sludge concentration.

[0008] Specifically, when the supply sludge concentration becomes high, the belt traveling speed is increased to reduce the solid load per unit filtration area. Conversely, when the sludge concentration becomes low, the belt running speed is reduced.

There is a method of automatically changing the inverter frequency of the drive motor to change the belt running speed.

[0010] In the third aspect of the present invention, the supplied sludge concentration is constantly measured with a thermometer, and the angle of the ramp (tilt plate) is automatically adjusted according to the change in the supplied sludge concentration. Specifically, when the sludge concentration becomes high, the ramp angle is reduced to weaken the concentration effect. Conversely, increase the ramp angle when the sludge concentration decreases.

There is a method of changing the ramp angle by moving the tip of the ramp up and down with an electrically driven bolt, an air cylinder, and a hydraulic cylinder.

A fourth aspect of the present invention is to constantly measure the concentration sludge concentration with a densitometer and automatically adjust the opening degree of the aggregating device (mixing valve) according to the change in the concentration sludge concentration. Specifically, when the concentration of concentrated sludge increases, the opening is increased to reduce the stirring force. Conversely, when the concentrated sludge concentration becomes low, the opening is reduced.

[0013] Measurement of the concentration of concentrated sludge uses a viscosity type, laser light type, microwave type, scattered light type, or the like. In addition, when using a concentrated sludge hopper and transferring the concentrated sludge by L and H operation of the concentrated sludge transfer pump, there is also a method to calculate the concentrated sludge concentration with the preset calculation function from the operation and stop time of the concentrated sludge pump. is there. The method for changing the belt running speed is the same as above.

[0014] In the fifth aspect of the present invention, the concentrated sludge concentration is constantly measured with a densitometer, and the belt running speed is automatically adjusted according to the change in the concentrated sludge concentration. Specifically, when the concentrated sludge concentration becomes high, the belt running speed is increased to lower the concentrated sludge concentration. Conversely, when the concentrated sludge concentration becomes low, the belt running speed is reduced.

[0015] In the sixth aspect of the present invention, the concentrated sludge concentration is constantly measured with a densitometer to match the change in the concentrated sludge concentration. Adjust the lamp angle automatically. Specifically, when the concentrated sludge concentration becomes high, the lamp angle is decreased and the concentrated sludge concentration is lowered. Conversely, when the concentrated sludge concentration is low, the ramp angle is increased. The method for changing the ramp angle is the same as described above.

The seventh aspect of the present invention constantly measures the filtrate concentration, and automatically adjusts the opening degree of the aggregating device (the rotation speed of the mixer) in accordance with the change in the filtrate concentration. Instead of the filtrate concentration, the SS recovery rate can be calculated and used by the controller from the three measured values of filtrate concentration, supply sludge concentration and concentrated sludge concentration. Specifically, when the filtrate concentration increases (when the SS recovery rate decreases), the opening degree is increased (the rotation speed of the mixer is decreased) to prevent the aggregation floc from being destroyed by the aggregator. The method for changing the opening of the agglomeration device (the number of rotations of the mixer) is the same as above.

For measuring the filtrate concentration, a concentration meter such as a scattered light type or a transmitted light type is used. The method for adjusting the opening of the aggregating device (orifice) is the same as described above, and there is also a method using a line mixer.

[0018] According to the eighth aspect of the present invention, the filtrate concentration is constantly measured, and the belt running speed is automatically adjusted in accordance with the change in the filtrate concentration. Specifically, when the filtrate concentration increases (when the SS recovery rate decreases), the belt running speed is increased to lower the solid load per unit filtration area. The method for changing the belt running speed is the same as above.

[0019] The ninth aspect of the present invention constantly measures the filtrate concentration and automatically adjusts the ramp angle in accordance with the change in the filtrate concentration. Specifically, when the filtrate concentration increases (when the SS recovery rate decreases), the ramp angle is reduced to lower the filtrate concentration. The method of changing the ramp angle is the same as above.

[0020] In a tenth aspect of the present invention, level sensors H and HH are provided on the belt, and the sludge on the belt is controlled so as not to exceed H. In other words, if the level becomes H or higher, the belt running speed is increased. When the level becomes HH, the belt type concentrator is stopped and an alarm is sounded. An electrode type is used for the level. The method for changing the belt running speed is the same as described above.

The No. ^-of the present invention is provided with level sensors H and HH on the belt, and controls so that the sludge on the belt does not exceed H. If the level is higher than H, decrease the ramp angle. When the level becomes HH, the belt type concentrator is stopped and an alarm is sounded. Use an electrode type for the level. The method for changing the ramp angle is the same as described above. [0022] The first power and eleventh control of the above invention may be performed independently, or may be performed in combination. Prioritize each control, and when the control is such that the opening or rotation speed of the coagulation device, the belt running speed, and the ramp (tilt plate) angle are operated in different directions, control with a higher priority is required. Do. In some cases, each control is weighted to determine the direction and degree of control.

[0023] Supply sludge concentration, concentrated sludge concentration, and filtrate concentration are constantly measured during belt type concentrator operation, and each operation control factor is automatically adjusted, so that the operation depends on the operator's sense. You don't need skill. Stable operation can be performed because constant operation adjustment is performed in response to changes in operating conditions. Operators go around the belt type concentrator during the patrol monitoring, which reduces operating costs and improves the working environment for operators. In addition, the operating cost can be reduced by preventing an increase in the amount of chemical injection and shortening the belt life.

Brief Description of Drawings

FIG. 1 is a view showing a belt type concentrator according to an embodiment of the present invention.

FIG. 2 is a diagram showing an aggregating device (mixing valve) used in the present invention.

FIG. 3 is a diagram illustrating various concentration meters of a belt type concentrator used in the present invention.

FIG. 4 is a diagram showing the operation of the lamp used in the present invention.

FIG. 5 is a view showing the operation of the valve of the aggregating apparatus used in the present invention.

FIG. 6 is a view showing the operation of a valve according to another example of the aggregating apparatus used in the present invention.

FIG. 7 is a diagram showing a level sensor on a belt used in the present invention and its operation.

FIG. 8 is a control diagram of case 1 where each measurement signal is combined.

FIG. 9 is a control diagram of case 2 where each measurement signal is combined.

FIG. 10 is a control diagram of Case 3 in which measurement signals are combined.

FIG. 11 is a control diagram of Case 4 where each measurement signal is combined.

FIG. 12 is a control diagram of Case 5 where each measurement signal is combined.

FIG. 13 is a control diagram of case 6 in which measurement signals are combined.

FIG. 14 is a control diagram of case 7 where each measurement signal is combined.

FIG. 15 is a control diagram of case 8 where each measurement signal is combined.

FIG. 16 is a more specific control diagram of the first embodiment of the invention. FIG. 17 is a more specific control diagram of the tenth embodiment of the invention.

FIG. 18 is a control diagram showing the embodiment of case 1 in FIG. 8 more specifically.

FIG. 19 is a view showing a means for changing the angle of a lamp provided in the belt type concentrator.

FIG. 20 is a view showing a means for changing the angle of a lamp provided in the belt type concentrator.

FIG. 21 is a diagram showing a configuration for measuring concentration by providing a concentration measurement tank.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described. As shown in FIG. 1, in the apparatus of this example, the supplied sludge is supplied to the coagulating apparatus 2, and the coagulated sludge conditioned in the coagulating apparatus 2 is once retained in the coagulating tank 3 on the supply side. Then, it is sent to the traveling belt la (filtration belt) via the supply chute 4 and gravity filtered on the belt, and the belt end terminal on the discharge side is also scraped off by the scraper 10 to be discharged as concentrated sludge. It is a belt type concentrator configured to be discharged from the factory.

[0026] When the power of the electric motor M is transmitted to the drive roller 6, the roller 6 rotates and the belt la travels in the direction of the arrow. The driven roller 5 rotates as the belt la travels. While the belt type concentrator 1 is in operation, the rollers 5 and 6 always rotate and the belt la runs. The filtered wave passing through the belt la is discharged via the outlet lc. Before the belt la returns to the supply side, it is washed with water spouted from the nozzle of the washing water pipe 8 and enters the next cycle. Wash water after washing is discharged through the outlet Id. Wash water may be recycled to the supply sludge side

[0027] The supplied sludge reacts with the polymer flocculant (polymer) in the aggregating apparatus 2 shown in FIG. 2 to become agglomerated sludge. The agglomeration device 2 is provided with a butterfly-shaped valve body 11 in the tubular mixing chamber and a plurality of high-molecular flocculant (polymer) introduction pipes 2a at the inlet of the mixing chamber, and adjusts the position of the valve body 11. As a result, the passage area in the aggregating apparatus 2 is changed, the stirring force is changed, and the degree of aggregation is adjusted. When the screw 2b is adjusted, the minimum angle of the valve body 11 is set, and this angle is maintained by the fixing weight 13 supported by the lever 12. In this structure, when the supply pressure (or flow rate) increases rapidly, the valve element 11 is automatically opened against the weight 13 to reduce the pressure. Valve opening The smaller the value, the greater the stirring action and the higher the degree of aggregation. If the degree of aggregation increases, the concentration of concentrated sludge increases. On the other hand, if the valve opening is too small, the agitation becomes too large and the flocs flocs are destroyed, reducing the concentration of concentrated sludge. In the example shown in FIG. 2, as the means for adjusting the opening degree, a method of adjusting the opening degree of the valve by the valve drive motor 18 as shown in FIG. 5 and a simpler structure as shown in FIG. For example, a method of adjusting the opening degree of the valve by moving the valve body 11 up and down with the valve drive motor 18 is possible.

As another method, there is a method in which the aggregating apparatus 2 is a line mixer instead of the valve mechanism described above, and the degree of aggregation is adjusted by the number of rotations. The larger the number of revolutions, the greater the stirring action, the higher the degree of aggregation, and the higher the concentration of concentrated sludge.

[0029] A professional mechanism 7 having a professional is arranged on the belt in several rows perpendicular to the running direction of the belt la, and the professional mechanism 7 in each row is provided with several blows (鋤). ing. It works to increase the filtration efficiency on the belt by spreading the sludge layer through the process.

[0030] The belt la runs at a variable speed of, for example, 8 to 40 m / min, depending on the structure of the filter medium. Concentrated sludge concentration changes by changing the running speed of the belt. As the running speed increases, the concentrated sludge concentration decreases.

[0031] A ramp (inclined plate) 9 is disposed close to the end of the belt la on the discharge side. Concentrated sludge is discharged beyond the lamp 9, but the ramp 9 prevents the concentrated sludge from being discharged, so that filtration at the belt la proceeds and the concentrated sludge concentration increases. The ramp angle (angle relative to the running surface of the belt la) is variable, and the concentration of concentrated sludge can be adjusted by changing the ramp angle. As the ramp angle increases, the concentrated sludge concentration increases.

[0032] Referring to Fig. 3, which is an embodiment provided with the control means of the concentrated sludge concentration and filtrate concentration (SS recovery rate) of the present invention, the supply sludge to be treated is fed to the inlet of the supply sludge aggregating apparatus 2. Concentration sludge meter 14 to measure concentration, concentrated sludge outlet 1 lb of belt type concentrator 1 Chute or tank le placed to concentrate sludge concentration meter 15 to measure concentrated sludge, and filtrate outlet 1 c A filtrate concentration meter 16 for measuring the concentration of the filtrate is installed in each chute or tank If. The concentration signal measured by each densitometer is sent to the control device 17, and the opening of the aggregating device 2 from the control device 17 (in the case of a line mixer, the number of rotations of the mixer), belt la Running speed, ramp (tilt) 9 angle actuation An operation command is issued.

[0033] Although the operation status of the belt-type concentrator changes depending on the supply sludge concentration, the valve opening of the coagulation device (the number of rotations of the mixer), the belt running speed, and the ramp angle should be adjusted automatically. The driving condition can be kept in good condition.

[0034] In accordance with the change in the measured value of the supplied sludge concentration meter 14 so that the pre-set chemical injection rate (the ratio of the polymer flocculant to the supplied sludge solids amount) with respect to the change in the supplied sludge concentration It is also possible to use a proportional dosing method in which the dosing amount is automatically and proportionally changed.

[0035] SS recovery rate (SS = sludge solid content) is calculated from the measured values of the supplied sludge concentration meter 14, the concentrated sludge concentration meter 15, and the filtrate concentration meter 16 using the controller, SS recovery rate = concentrated sludge concentration s [%] (Supply sludge concentration f [%] — filtrate concentration e [%]) / Supply sludge concentration f [%] (Concentrated sludge concentration s [%] — filtrate concentration e [%]) Calculated as X 100 It is also possible to do. If only the sign is used,

SS recovery rate = 100 X [s (f— e)] Z [f (s— e)]%

It is.

[0036] In the first method of the present invention, the supplied sludge concentration is constantly measured with a densitometer, and the opening degree of the flocculating device (mixing valve) is automatically adjusted in accordance with the change in the supplied sludge concentration. Specifically, when the sludge concentration becomes high, the opening is reduced and the stirring force is increased. Conversely, increase the opening when the sludge concentration is low. For example, when the operation was performed at an ideal concentrated sludge concentration of 4%, the supply sludge concentration increased, and when the concentrated sludge concentration was about 4%, the signal from the supply sludge concentration meter 14 The controller 17 detects an increase in the supply sludge concentration and issues an operation command to reduce the angle of the valve body of the agglomeration device (increase the rotational speed of the mixer) as shown in Figs. 5 and 6. Increase the concentration of sludge and keep the concentrated sludge concentration at 4%. Conversely, when the supplied sludge concentration is lowered and the concentrated sludge concentration is going to fall below 4%, the angle of the valve body is increased (the rotation speed of the mixer is reduced) to prevent the destruction of the floc flocs and the concentrated sludge concentration. To 4%.

[0037] FIG. 16 shows a control method for carrying out this method. As a premise, the controller repeats the measurement, comparison and control of the concentration and sludge level on the belt at regular time intervals by the timing pulse from the time counter.

[0038] In Fig. 16, there is an appropriate concentration range for the supplied sludge concentration, and agglomeration occurs even outside this range If the degree is appropriate, the above 4% concentrated sludge concentration can be obtained. First, if the supplied sludge concentration is higher than the upper limit of the appropriate range (YES), the opening of the coagulator (valve) is decreased, and if the opening is higher than the lower limit (NO), the decrease of the opening is repeated step by step. To agglomerate the supplied sludge (loop 1). Conversely, if the supply sludge concentration is less than the lower limit of the appropriate range (YES), increase the opening, and if the opening is greater than the upper limit (NO), repeat the increase of the opening in steps to properly aggregate the supplied sludge. (Loop 2). If the feed sludge concentration is neither of these (ie, within the proper range), it returns directly to the starting point (loop 3) and repeats judgment and control.

[0039] Since the second to ninth embodiments of the present invention can be configured in the same manner as the embodiment of Fig. 16, a detailed control flow diagram will not be described, but a basic control method will be described below.

[0040] In the second method of the present invention, when the control device 17 detects a decrease in the supply sludge concentration based on the signal from the supply sludge concentration meter 14, the belt running shown in FIG. By reducing the line speed, the concentrated sludge concentration can be maintained at 4%.

[0041] Further, in the third method of the present invention, the concentration of the sludge is increased by 4% by increasing the angle of the lamp 9 shown in FIG. 3 by the operation command from the control device 17 by the signal from the supply sludge concentration meter 14. Can be maintained.

In the fourth method of the present invention, the opening degree of the aggregating device (valve) is automatically adjusted according to the change in the concentrated sludge concentration measured by the concentrated sludge concentration meter 15.

[0043] When the concentrated sludge densitometer 15 is used as a sensor for detecting changes in the operating status, when the measured value of the concentrated sludge densitometer is lower than the set value, the opening of the aggregating device is reduced (mixer). In some cases, the number of revolutions is increased (in the case of a mixer), and in some cases (in the case of a mixer, the number of revolutions is reduced). In the case of sludge flocculation, if the agitation force by the flocculation device 2 is too large, the flocculation floc will be destroyed, and if it is too small, flocculation will be poor. Therefore, there is an optimum point where the stirring force is not too large and not too small. In this case, in the feedback control, an operation that changes to the upper limit determined in advance in order to find the optimum point, and changes to the lower limit if it is not appropriate is incorporated. The appropriate range is determined by the concentrated sludge concentration.

[0044] In the fifth method of the present invention, when the signal from the concentrated sludge concentration meter 15 becomes lower than the set value, the controller 17 issues an operation command for reducing the traveling speed of the belt la shown in FIG. In some cases, the control is performed to keep the concentrated sludge concentration at a set value. When the concentrated sludge concentration becomes high, the reverse operation command is issued.

[0045] In the sixth method of the present invention, when the signal from the concentrated sludge concentration meter 15 becomes lower than the set value, the control device force is operated to increase the angle of the ramp (inclined plate) 9 as shown in FIG. In some cases, a command is issued to control the concentration of concentrated sludge at a set value. When the concentrated sludge concentration becomes high, the reverse operation command is issued.

[0046] In the seventh method of the present invention, when the measured value of the filtrate concentration meter 16 becomes higher than the set value, the interval between the valves of the aggregating device 2 is decreased (the rotational speed of the mixer is increased) and May be larger (smaller). In the same way as the control by concentrated sludge concentration, this feedback control changes up to the upper limit decided in advance to find the optimum point, and if it does not become appropriate, an operation that changes toward the lower limit is incorporated. When using the calculated value of the SS recovery rate by the control device instead of the measured value of the filtrate concentration meter, perform the same control when the calculated value of the SS recovery rate falls below the set value. The appropriate range in this case is judged by the filtrate concentration or SS recovery rate.

In the eighth method of the present invention, when the measured value of the filtrate concentration meter 16 becomes higher than the set value, the running speed of the belt la shown in FIG. 3 is increased by the operation command from the control device 17. But the filtrate concentration can be reduced. When using the calculated value of the SS recovery rate by the control device instead of the measured value of the filtrate concentration meter, the same control is performed when the calculated value of the SS recovery rate becomes lower than the set value.

[0048] In the ninth method of the present invention, when the measured value of the filtrate concentration meter 16 becomes higher than the set value, the angle of the ramp (tilt plate) 9 shown in FIG. The filtrate concentration can also be reduced by making it smaller. When using the calculated value of SS recovery rate by the controller instead of the measured value of the filtrate concentration meter, the same control is performed when the calculated value of SS recovery rate is lower than the set value.

[0049] In the tenth method of the present invention, as shown in FIG. 7, the saddle belt on-belt level sensors 19 and 20 can be provided as sensors for detecting changes in the driving situation. Two levels are used for level detection: high level H19 and ultra high level HH20. If the filtration progress is good on the belt, the sludge level on the belt is low.If the filtration progress is poor, the sludge level on the belt is low. The price increases.

[0050] Therefore, whether the driving condition is good or not can be determined based on the sludge level on the belt. The level sensor always detects the sludge level and keeps the sludge level in good condition. For example, if the sludge level sensor 19 detects a high level H, an operation command is issued from the control device 17, and the sludge level is lowered by increasing the belt running speed. If level sensor 20 detects ultra-high level HH, the belt type concentrator is stopped and an alarm is sounded.

[0051] Fig. 17 shows a specific control method of the tenth method. In this figure, if the measured height value is greater than 11, the operation is stopped and an alarm is sounded. If between H and HH, increase belt speed towards upper speed limit (Loop 1). If the height drops below H on the way, move to loop 2. Initial force If this condition is satisfied, return from loop 2 to the beginning, and repeat judgment and control. If the belt speed exceeds the upper limit, alarm or change the control type.

[0052] As the ^ -th method of the present invention, if the high level H is detected, the sludge level is lowered by decreasing the ramp (tilt plate) angle by the operation command from the control device 17. If ultra-high level H H is detected, operation of the belt-type dark Hakone is stopped and an alarm is sounded.

[0053] When control is performed in combination with signals from the supplied sludge concentration meter 14, the concentrated sludge concentration meter 15, the filtrate concentration meter 16, and the sludge level meters 19 and 20 on the belt, it is as follows. Table 1 shows the classification of each signal. The reference value of the supplied sludge concentration is determined in advance, for example, 0.6 to 0.7% based on the measured value. For the set value of the concentrated sludge concentration, the optimum range is determined in advance, for example, 4.0 to 4.2%, taking into account the operation of the subsequent process. The filtrate concentration is good in the low range, and the SS recovery rate is good in the high range. For example, a filtrate concentration of 0.3% or less and an SS recovery rate of 95% or more are good, and a filtrate concentration of more than 0.3% and an SS recovery rate of less than 95 are considered bad.

[0054] [Table 1] Low

Donated sludge concentration standard value

High

Low

«Shrinkage sludge concentration setting value

High

Low (high)

Filtrate concentration (s S recovery)

髙 (Low)

Super high

Sludge on bell

[0055] As shown in FIGS. 8 to 15, there are eight types of operation commands for outputting the control device by combining each measurement signal.

[0056] That is, among the combinations of the supplied sludge concentration Cl, the concentrated sludge concentration C2, the filtrate concentration C3 (SS recovery rate), and the sludge height H on the belt, the supplied sludge concentration is a reference value (generally there is a range). ), It can be controlled by changing C2 and C3, and C1 defines C2 and C3 to some extent. Cases 1 to 8 determine the level of each of the three measured concentrations using a comparison circuit and determine which case corresponds to the combination of these three types of levels (described below) to the NAND gate. What is necessary is just to judge.

[0057] Case 1 shown in Fig. 8 is a case where the supply sludge concentration is low, the concentrated sludge concentration is low, and the filtrate concentration is low (SS recovery rate is high). Increase (decrease mixer speed). If the situation in Case 1 is not improved even after changing to the upper limit (lower limit), the opening degree of the aggregating device (mixer rotation speed) is set to the optimum point, and if the sludge level on the belt does not exceed H, Increase the ramp (tilt) angle step by step. When the ramp angle reaches the upper limit, the belt running speed is reduced stepwise.

[0058] If the situation in Case 1 is not improved even if the belt running speed is lowered to the lower limit, the set concentrated sludge concentration is lowered step by step. For example, when the current set value is 4.0 to 4.2%, change the set value to 3.8 to 4.0%, and if the concentrated sludge concentration still does not reach the set value, set the set value to 3.6. Change to ~ 3.8%. Decide the lower limit value of the set value in advance, and sound an alarm to notify the operator when the set value reaches the lower limit value. If the filtrate concentration is high (SS recovery rate is low) or the sludge level on the belt exceeds H during this control, the operation of the ramp and belt running speed is stopped and the operation starts to lower the set concentrated sludge concentration. FIG. 18 shows a flow of determination and control for specifying case 1 shown in FIG. However, the set sludge concentration is low (for example, less than 0.6 to 0.7%), the concentrated sludge concentration is low (for example, less than 4.0 to 4.2%), and the filtrate concentration is low (SS recovery rate is high). (For example, less than 0.3% (SS recovery rate is over 95%)).

[0060] In Fig. 18, when the supply sludge concentration is lower than the lower limit (YES), the concentrated sludge concentration is less than the set value (YES), and the filtrate concentration is less than the set value (YES) (SS recovery rate set value exceeds the upper limit (YES)), Increases the opening of the aggregator. If the upper limit is not exceeded (NO), loop 1 will be repeated. When the opening exceeds the upper limit (YES), the opening of the aggregator is returned to the reference value, and when the sludge level on the belt is not more than H (NO), the ramp angle is increased. If the ramp angle is less than the upper limit (YES), loop 2 will be repeated. If the ramp angle is not less than the upper limit (NO), if the sludge level on the belt is not higher than H (NO), decrease the belt speed. If belt speed is above the lower limit (YES), repeat loop 3. If the belt speed does not exceed the lower limit (NO), decrease the concentrated sludge concentration setting value. If the concentrated sludge concentration set value is above the lower limit (YES), return to the beginning in loop 4 and repeat the same control. If the concentrated sludge concentration set value is not above the lower limit (NO), the system is stopped and a warning is issued.

[0061] It will be apparent to those skilled in the art that the example described below can easily determine the flow of determination and control as described above.

[0062] Case 2 shown in Fig. 9 is a case where the supply sludge concentration is low, the concentrated sludge concentration is low, and the filtrate concentration is high (SS recovery rate is low). Decrease the number). If the situation in Case 1 is not improved even after changing to the upper limit (lower limit), the opening of the coagulator (mixer rotation speed) is returned to the standard value, and the set concentrated sludge concentration is lowered stepwise as described above.

[0063] Case 3 shown in Fig. 10 is a case where the supply sludge concentration is high, the concentrated sludge concentration is low, and the filtrate concentration is low (SS recovery rate is high). Increase the rotation speed). If the situation in Case 1 is not improved even if the value is changed to the lower limit (upper limit), the opening degree of the aggregator (mixer rotation speed) returns to the reference value, and if the sludge level on the belt does not exceed H, the ramp (inclined plate ) Increase the angle step by step. When the ramp inclination angle reaches the upper limit, the belt running speed is gradually reduced. [0064] If the situation in Case 1 is not improved even if the belt running speed is lowered to the lower limit, the set concentrated sludge concentration is lowered step by step. For example, when the current set value is 4.0 to 4.2%, change the set value to 3.8 to 4.0%, and if the concentrated sludge concentration still does not reach the set value, set the set value to 3.6. Change to ~ 3.8%. Decide the lower limit value of the set value in advance, and sound an alarm to notify the operator when the set value reaches the lower limit value. If the filtrate concentration is high (SS recovery rate is low) or the sludge level on the belt exceeds H during this control, the operation of the ramp and belt running speed is stopped and the operation starts to lower the set concentrated sludge concentration.

[0065] Case 4 shown in Fig. 11 is a case where the supply sludge concentration is high, the concentrated sludge concentration is low, and the filtrate concentration is high (SS recovery rate is low). Increase). If the situation in Case 4 is not improved even if the value changes to the lower limit (upper limit), the opening degree of the agglomeration device (mixer rotation speed) is returned to the reference value, and the set concentrated sludge concentration is lowered stepwise in the same manner as above.

[0066] Case 5 shown in Fig. 12 is a case where the concentrated sludge concentration is low and the filtrate concentration is low (SS recovery rate is high). If the sludge on-belt level force ¾ is not exceeded, the lamp (inclined plate) Increase the angle step by step. When the ramp inclination angle reaches the upper limit, the belt running speed is gradually reduced. If the situation in Case 1 is not improved even if the belt running speed is lowered to the lower limit, the set concentrated sludge concentration is lowered step by step. For example, if the current set value is 4.0 to 4.2%, change the set value to 3.8 to 4.0% .If the concentrated sludge concentration still does not reach the set value, change the set value to 3. Change to 6 to 3.8%. The lower limit value of the set value is determined in advance, and an alarm is sounded to notify the operator when the set value reaches the lower limit value. If the filtrate concentration is high (SS recovery rate is low) or the sludge level on the belt exceeds H during this control, the operation of the ramp and belt running speed is stopped, and the operation starts to reduce the set concentrated sludge concentration.

[0067] Case 6 shown in Fig. 13 is a case where the concentrated sludge concentration is low and the filtrate concentration is high (SS recovery rate is low), and the set concentrated sludge concentration is gradually reduced. For example, if the current set value is 4.0 to 4.2%, change the set value to 3.8 to 4.0%, and if the concentrated sludge concentration still does not reach the set value, set the set value to 3. Change to 6 to 3.8%. The lower limit value of the set value is determined in advance, and an alarm is sounded to notify the operator when the set value reaches the lower limit value.

[0068] Case 7 shown in Fig. 14 is for the case of high concentrated sludge concentration and low filtrate concentration (high SS recovery rate). Yes, reduce the angle of the ramp (tilt plate) step by step. When the ramp inclination angle reaches the lower limit, the belt running speed is increased stepwise. If the situation in case 7 is not improved even if the belt running speed is increased to the upper limit, the set concentrated sludge concentration is increased stepwise. For example, if the current set value is 4.0 to 4.2%, change the set value to 4.2 to 4.4%. If the concentrated sludge concentration still does not reach the set value, change the set value to 4.4 to 4. Change to 6%. The upper limit value of the set value is determined in advance, and when the set value reaches the upper limit value, an alarm is sounded to notify the operator.

[0069] Case 8 shown in Fig. 15 is a case where the concentrated sludge concentration is high and the filtrate concentration is high (SS recovery rate is low), and the angle of the ramp (inclined plate) is gradually reduced. When the ramp inclination angle reaches the lower limit, the belt running speed is increased stepwise. If the situation in Case 8 is not improved by increasing the belt running speed to the upper limit, or if the filtrate concentration is high (SS recovery rate is low), an alarm is sounded to inform the operator. If the filtrate concentration is high (SS recovery rate is low) and the concentrated sludge concentration is not improved, the set concentrated sludge concentration is increased stepwise. For example, if the current set value is 4.0 to 4.2%, change the set value to 4.2 to 4.4% .If the concentrated sludge concentration still does not reach the set value, change the set value to 4. Change to 4 to 4.6%. The upper limit value of the set value is determined in advance, and an alarm is sounded to notify the operator when the set value reaches the upper limit value.

[0070] As described above, as the means for changing the angle of the lamp 9, an electrically driven bolt, an air cylinder, a hydraulic cylinder, or the like can be used. Here, an example in which a cylinder mechanism is used as means for changing the angle of the ramp 9 will be described with reference to FIGS. 19 and 20. FIG. First, the lamp 9 is composed of a metal plate 91 such as stainless steel and a resin plate 92 having a tapered cross section formed of fluorine resin or the like. The metal plate 91 is supported by a bar member 93, and a pair of connecting members 94A and 94B are provided at both ends of the bar member 93. Further, the connecting members 94A and 94B are rotatably connected with cylindrical members 95A and 95B provided on the side walls of the apparatus as rotation axes. Therefore, the ramp 9 can arbitrarily change the inclination angle Θ in accordance with the rotation of the connecting members 94A and 94B. Reference numeral 96 in FIG. 20 is a side wall for preventing sludge from falling on both sides of the running belt la, and is omitted in the other drawings for convenience of drawing. Further, rod members 98A, 98B passing through arcuate guide grooves 97 formed on the side walls of the apparatus are connected to the other end sides of the connecting members 94A, 94B. The motor cylinder mechanism 100, which is an angle changing means, is connected to one of the rod members (98A). The motor cylinder mechanism 100 includes a motor 101 that can be braked halfway and a cylinder 102 that is extended by the motor 101. Then, the control device 17 refers to the sludge concentration value measured by the sludge densitometer 15 every predetermined time, and extends the cylinder 102 according to the referred concentration value, and changes the inclination angle Θ of the lamp 9 stepwise. Can be controlled.

[0072] By configuring the angle changing means of the lamp 9 as described above, the angle of the lamp 9 can be automatically changed without depending on the operator.

[0073] Finally, the installation location of the concentrated sludge concentration meter 15 is not limited to the tank le. As shown in FIG. 21, a measuring tank 110 for concentration measurement is provided separately from the tank le, and the concentration is performed from the tank le. The sludge can be sampled and the concentration measured. In the example shown in FIG. 21, a configuration using a viscosity type densitometer as the concentrated sludge densitometer 15 is described.

That is, as shown in FIG. 21, the measurement tank 110 for concentration measurement is connected to the tank le via a pipe, and the concentrated sludge for measurement is continuously supplied to the measurement tank 110 to obtain a concentrated sludge concentration meter. 15 is a configuration in which the concentration is continuously measured. The concentrated sludge densitometer 15 detects a detector 111 composed of a disk-shaped rotating disk, a drive motor 112 that rotates the detector 111 in the concentrated sludge around the rotation axis, and a current value of the drive motor 112. For example, a converter 113 that converts to an electric signal of 4 20 mA, and a calculator 114 that calculates the sludge concentration based on the electrical signal from the converter 113, the viscosity corresponding to each concentration Calculate the concentration using the difference.

[0075] More specifically, correlation information (for example, a correlation equation) that associates the sludge concentration with a current value (actually an electric signal having a transformation force) when the detection body 111 is rotated at a predetermined number of rotations. And database), the information is stored in the storage means of the computing unit 114, for example, in memory, and the correlation is determined based on the electric signal sent from the variable 13 in the actual device. It is the structure which calculates sludge density | concentration with reference. Note that the converter 113 may detect the torque value of the drive motor 112 instead of the current value. [0076] If a viscometer type densitometer as described above is adopted and the concentration tank is not installed directly in the tank le, the measurement tank 110 for concentration measurement is installed separately. Therefore, it is possible to reduce the resistance caused by the sludge flow that can contribute to the measurement of the concentration of sludge concentrated to 4% or more continuously and accurately. It is out.

[0077] While specific embodiments of the present invention have been described above, it is obvious to those skilled in the art that various modifications can be made without departing from the scope of the present invention. It is a thing. Therefore, the technical scope of the present invention should be determined based on the scope of claims and equivalents thereof, not limited to the above-described embodiments.

Claims

The scope of the claims

[1] Consisting of a roller and an endless belt that covers the roller, and a drive means that drives the roller. Supply the agglomerated sludge onto the endless belt that travels, and supply it in a belt type concentrator that performs filtration and concentration by gravity. Measure continuously with one or more of the measuring instruments of sludge concentration, concentrated sludge concentration, filtration concentration and sludge level on the belt, and the opening of the agglomeration device or the rotation speed of the mixer in response to changes in these measured values The belt-type concentrator is characterized in that the concentrated sludge concentration and filtrate concentration (SS recovery rate) are controlled within a predetermined range by automatically changing one or more of the belt running speed and ramp angle. .

[2] The sludge level measuring device on the belt has a first sensor that measures the standard level H and a second sensor that measures the upper limit level HH, so that the sludge level on the belt does not exceed H! /, Thus, when the level exceeds H, the belt traveling speed is increased and the Z or ramp angle is decreased, and when the level becomes HH, the operation of the belt type concentrator is stopped with an alarm. A belt type concentrator as described in 1.

[3] Supply sludge concentration, concentrated sludge concentration, filtrate concentration, and sludge level on the belt are continuously measured by each measuring instrument. Adjust the operation by automatically changing the running speed and ramp angle, and if the control direction differs according to each measured value, set the priority or weight of the control and keep the setting of the coagulation device at the appropriate value 2. The belt-type concentrator according to claim 1, wherein the belt-type concentrator reduces the power consumption and lengthens the life of the belt by preventing an increase in the amount of chemical injection and maintaining the belt running speed at an appropriate value.

[4] When the supply sludge concentration is low, the concentrated sludge concentration is low, and the filtrate concentration is low (SS recovery rate is high), the opening degree of the coagulation device (mixing valve) is increased stepwise (decreasing the mixer rotation speed) If the set concentrated sludge concentration is not achieved even if the upper limit (lower limit) is reached, the coagulator opening (mixer rotation speed) returns to the reference value, and if the sludge level on the belt does not exceed H, the ramp When the (tilt plate) angle is increased stepwise and the ramp inclination angle reaches the upper limit, the belt travel speed is decreased stepwise, and even if the belt travel speed is decreased to the lower limit, 4. The belt type concentrator according to claim 3, wherein when the reduced sludge concentration is not achieved, the set concentrated sludge concentration is decreased stepwise.

[5] When the supply sludge concentration is low, the concentrated sludge concentration is low, and the filtrate concentration is high (SS recovery rate is low), increase the coagulator opening stepwise (decrease the mixer rotation speed) and set the upper limit (lower limit). If the set concentrated sludge concentration is not achieved even if the pressure is changed to 1, the coagulator opening (mixer rotation speed) is returned to the reference value, and if the sludge on the belt level force ¾ is not exceeded, the angle of the ramp (tilt plate) When the ramp inclination angle reaches the upper limit, the belt running speed is reduced stepwise, and even if the belt running speed is lowered to the lower limit, the set concentrated sludge concentration is reduced. 4. The belt type concentrator according to claim 3, wherein when it is not achieved, the set concentrated sludge concentration is decreased stepwise.

[6] When the supply sludge concentration is high, the concentration sludge concentration is low, and the filtrate concentration is low (SS recovery rate is high), the opening degree of the coagulator is gradually reduced (the mixer rotation speed is increased), and the lower limit (upper limit) If the situation in Case 1 is not improved even after changing to 1, the agglomeration device opening (mixer speed) returns to the reference value, and if the sludge level on the belt does not exceed H, the ramp (tilt plate) When the angle is increased stepwise and the ramp inclination angle reaches the upper limit, the set sludge concentration satisfies the set value even if the belt running speed is lowered stepwise and the belt running speed is lowered to the lower limit. 4. The belt type concentrator according to claim 3, wherein if not, the set concentrated sludge concentration is lowered stepwise.

[7] When the supply sludge concentration is high, the concentrated sludge concentration is low, and the filtrate concentration is high (SS recovery rate is low), the opening of the agglomeration device is reduced stepwise (increasing the mixer rotation speed), and the lower limit (upper limit) 4. If the set concentrated sludge concentration is not achieved even if the temperature is changed, the agglomeration device opening (mixer rotation speed) is returned to the reference value, and the set concentrated sludge concentration is lowered stepwise. Concentrator.

[8] When the sludge concentration is low and the filtrate concentration is low (SS recovery rate is high), if the sludge level on the belt does not exceed H, the angle of the ramp (inclined plate) is increased stepwise. When the ramp inclination angle reaches the upper limit, the concentrated sludge concentration does not improve even if the belt traveling speed is reduced stepwise and the belt traveling speed is lowered to the lower limit. 4. The belt-type concentrator according to claim 3, wherein the degree is lowered stepwise.

[9] When the concentrated sludge concentration is low and the filtrate concentration is high (SS recovery rate is low), the set concentrated sludge concentration is decreased stepwise, and if the concentrated sludge concentration still does not reach the set value, set the set value. The belt-type concentrator according to claim 3, which is changed.

[10] When concentrated sludge concentration is high and filtrate concentration is low (SS recovery rate is high), when the ramp (tilt plate) angle is gradually reduced and the ramp tilt angle reaches the lower limit, the belt travels. The belt type according to claim 3, wherein if the set concentrated sludge concentration is not achieved even if the speed is increased stepwise and the belt running speed is increased to the upper limit, the set concentrated sludge concentration is increased stepwise. Concentrator.

[11] When the concentrated sludge concentration is high and the filtrate concentration is high (SS recovery rate is low), when the ramp (tilt plate) angle is gradually reduced and the ramp tilt angle reaches the lower limit, the belt travels. Even if the speed is increased stepwise and the belt running speed is increased to the upper limit, an alarm is given if the high filtrate concentration (SS recovery rate) is not improved. 4. The belt type concentrator according to claim 3, wherein when the concentration of concentrated sludge is not improved but the set concentration sludge concentration is increased step by step.

[12] A cylinder mechanism for changing the inclination angle of the ramp and a control device for controlling the operation of the cylinder mechanism are provided, and the control device displays the measurement result of the concentrated sludge concentration by the measuring device at predetermined time intervals. 12. The belt-type concentrator according to claim 1, wherein the inclination angle of the ramp is changed stepwise according to the reference measurement result.

[13] Belt-type concentrator power A measurement tank for sampling the concentrated sludge discharged is provided, and a concentration-type concentrated sludge concentration meter is installed in the measurement tank to measure the concentrated sludge concentration. The belt type concentrator according to any one of claims 1 to 12.